Accurate three-dimensional maps of external and internal human body surfaces are necessary for many medical procedures. For example, external body surfaces may need to be scanned for facial reconstructive surgery or the fitting of prosthetics. Internal body surfaces may need to be mapped for various endoscopic or catheter-based procedures, such as virtual biopsy, stenting, ablation, bronchoscopy, esophogastrodenoscopy, laparoscopy, colonoscopy, cyctoscopy, or arthroscopy. Further, some internal procedures may take place in gaseous media, such as a bronchoscopy, and others may take place in liquid media, such as arthroscopy or cardiovascular visualization.
Current techniques for three-dimensional scanning external and internal body surfaces have many drawbacks. Laser-based scanning, such as a laser line scan, typically requires a patient to remain motionless, with even minor movements affecting the accuracy of the scan. A typical laser scan may require a patient to sit still for ten to fifteen seconds while many two-dimensional slices are gathered. The two-dimensional slices are later recompiled into a three-dimensional representation of a surface. Movement during this time period by the patient, including respiration, tremors, or muscle reflexes, can negatively impact the accuracy of the scan. Further, laser scanning equipment itself may introduce unwanted vibration into the system due to the inherent movement of the laser.
Commonly used techniques for internal organ measurements suffer from similar induced errors, these methods include: computed tomography (CT), optical coherence tomography (OCT), magnetic resonance imaging (MRI), and various ultra-sound approaches (US and IVUS).
Thus, a need exists for three-dimensional surface measurement techniques that may be performed quickly and may eliminate inaccuracies introduced by patients and equipment.